Waterjet steering and reversing mechanism

ABSTRACT

Directional control apparatus for waterjet powered marine vessels comprising a machanism which will steer and reverse the waterjet exit stream with the force applying actuators located inside the ship&#39;&#39;s hull. The mechanism consists of a steering tube pivotally mounted at the exit of the waterjet stream about a vertical axis on a support structure attached to the ship&#39;&#39;s hull. The tube is turned by a vertical shaft attached to the upper end of the tube which passes through the hull and is terminated by a perpendicularly attached arm. The latter is to be operated by an actuator contained within the hull. The thrust reversing mechanism utilizes an actuator system similar to the steering mode which consists of a shaft concentric with the steering tube shaft and similarly operated by a perpendicularly attached arm and actuator contained within the hull. The reverser comprises a deflector having a forwardly and downwardly directed construction which is pivoted about the same vertical axis as the tube so as to provide a forward (no blockage), neutral (semi-blockage) and reverse (full blockage) mode of operation at any steering angle.

United States atent H 1 Delfeld WATERJET STEERING AND REVERSING MECHANISM William H. Delfeld, Bellevue, Wash.

The Boeing Company, Seattle, Wash.

Filed: June 25, 1973 Appl. No.: 378,562

Inventor:

Assignee:

References Cited UNITED STATES PATENTS 10/1967 Warren 115/12 X ll/l969 Fox 115/12 R 10/1971 Veldhuizen 115/12 R Primary Examiner-Trygve M. Blix Attorney, Agent, or Firm--Nico1aas DeVogel Apr. 30, 1974 [57] ABSCT Directional control apparatus for waterjet powered marine vessels comprising a machanism which will steer and reverse the waterjet exit stream with the force applying actuators located inside the ships hull. The mechanism consists of a steering tube pivotally mounted at the exit of the waterjet stream about a vertical axis on a support structure attached to the ships hull. The tube is turned by a vertical shaft attached to the upper end of the tube which passes through the hull and is terminated by a perpendicularly attached arm. The latter is to be operated by an actuator con tained within the hull. The thrust reversing mechanism utilizes an actuator system similar to the steering mode which consists of a shaft concentric with the steering tube shaft and similarly operated by a perpendicularly attached arm and actuator contained within the hull.'The reverser comprises a deflector having a forwardly and downwardly directed construction which is pivoted about the same vertical axis as the tube so as to provide a forwardjno blockage), neutral (semi-blockage) and reverse (full blockage) mode of operation at any steering angle.

8 Claims, 8 Drawing Figures WATERJET STEERING AND REVERSING MECHANISM I BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to marine vessels and more particularly to directional control of waterjet propelled marine vessels.

2. Description of the Prior Art The present invention is directed to marine vessels of the jet-propelled variety wherein means are utilized to expel a jet of water rearwardly of the vessel. By this invention it is contemplated to deflect this emerging jet of water so as to change the direction of travel of the vessel both as toport and starboard as well as forward and reverse, individually and in combination.

Marine vessels employing waterjet propulsion means operate on the principle of drawing ambient water through an inlet located in the vessels hull and pumping it through a duct with an exit directing the resultant waterjet aft thus propelling the vessel forward. One of the major advantages of such a propulsion system is its ability to operate a vessel where there is only sufficient water level to support the vessels draught. It is desirable, therefore, to minimize any projections on the underside of the vessel. The propulsion system tends to ingest sand and sedementary material when operating at near minimum depths. Likewise, such propulsion systems operate in fresh water and salt water environments alike. The basic propulsion system, however, does not provide a capability for operating the vessel in a reverse direction which is disadvantageous when maneuvering in confined areas and in other circumstances.

One problem with much of the prior art teaching is that it requires placing the actuating mechanisms in close proximity to the waterjet deflecting means. Not only does this place the actuating mechanisms within the operating environment previously described, but requires a multitude of holes through the vessels hull to connect the external actuators to the internal control mechanisms.

Another problem with prior art teaching is the extensive use of metal to metal sliding movement within the deflecting and actuating means. Such use of metal to metal contact within the operational environment would be prone to frequent malfunction and high maintenance factors. In addition, much of the prior art teaching discloses complex parts which would be difficult to maintain, requiring replacement of parts rather than repair.

Many applications of waterjet propelled marine vehicles are directly related to military operations and support in remote locations. Still others are related to marine hydrofoil applications in which such vessels operate over long distances and for long durations of time away from repair and maintenance facilities. Therefore, a primary objective of the present invention is to provide directional control for waterjet propelled ma rine vessels which can be located above the waterline so as to reduce drag and minimize underwater projections.

Another objective of the present invention is to provide directional control for waterjet propelled marine vessels with a minimum of metal to metal contact within the operative mechanism and to associated vessel structures.

A further objective of the present invention is to provide directional control for waterjet propelled marine vessels which is simple in design and operation so as to reduce original cost of construction, reduce cost of maintenance, and minimize fouling while maximizing ease of operation in an environment of corrosive salt water, sand and sediment, and high water pressures.

Still another objective of the present invention is to provide directional control for waterjet propelled marine vessels in which the actuating mechanism can be placed in a protected environment, moving parts operating'in the water will be minimal, and amount of hull penetration for mounting and operation will be minimal.

Yet another objective of the present invention is to provide directional control for waterjet propelled marine vessels combining steering and forward/reverse in one unit which allows steering in reverse and a smooth transition from forward to reverse.

Other objects and advantages of the present invention will become obvious from the detailed description of operation and the claims. The preferred embodiment is depicted in the figures and description that follow hereinafter.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of the invention as attached to the rear hull of a waterjet powered vessel and wherein the control mechanism is set to effect forward movement of the vessel.

FIG. 2 is a side elevation of the invention as attached to the rear hull of a waterjet powered vessel and wherein the control mechanism is set to effect rearward movement of the vessel.

FIG. 3 is a top view of the invention as attached to the rear hull of a waterjet powered vessel and wherein the control mechanism is set to effect forward movement of the vessel as depicted in FIG. 1 with no port or starboard deflection.

FIG. 4 is a top view of the invention as attached to the rear hull of a waterjet powered vessel and wherein the control mechanism is set to effect rearward movement of the vessel as depicted in FIG. 2 with no port or starboard deflection.

FIG. 5 is a simplified top view of the inventions deflectors operating in the forward direction.

FIG. 6 is a simplified top view of the inventions deflectors operating in a neutral position.

FIG. 7 is a simplified top view of the inventions deflectors operating in a reverse direction.

FIG. 8 is a top view of the invention as attached to the rear hull of a waterjet powered vessel and wherein the control mechanism is set to effect forward movement of the vessel while causing a change of direction in the port direction. The ghost position of the mechanism as shown in the same figure will cause forward movement of the vessel while causing a change of direction in the starboard direction.

DESCRIPTION AND OPERATION OF THE INVENTION The present invention provides both a forwardreverse and a steering capability to a waterjet powered marine vessel. In operation, a waterjet propulsion system draws ambient water through an inlet duct with a pumping means and discharges the water under pressure. The resulting waterjet in the accompanying figures causes a propulsion force on the marine vessel in a direction opposite its final flow direction. If the waterjet 10 is deflected in any direction the resultant force vector on the marine vessel will be changed accordingly. The present invention operates to cause such deflections of the emerging waterjet 10. By deflecting the waterjet 10 laterally only, as shown in FIG. 8, the marine vessel can be steered while traveling in the forward direction. By deflecting the waterjet 10 down and forward only, as shown in FIG. 2, the marine vessel can travel in a straight backwards direction. By deflecting the waterjet 10 in combination both laterally and down-and-forward, the marine vessel can be steered while traveling in reverse.

Referring to FIG. 1, the waterjet l0 emerges from the duct exit 12 in the vessels transom l4. Reversing deflector l6 and steering deflector 18 are positioned and attached to the transom 14 by mounting means which hold the deflectors 16 and 18 such that they may be pivoted easily as will be described while being secure and steady in the force of the emerging waterjet 10.

The steering deflector 18 is carried by a steering shaft 22 which passes through bearing and sealing assembly 24 into the vessels interior or a protective enclosure 26 terminating in a steering arm 28.

The reversing deflector 16 is carried by a reversing shaft 30 which passes through bearing and sealing assembly 24 into the vessels interior or a protective enclosure 26 terminating in a reversing arm 32.

FIG. 3 and FIG. 4 provide a clearer view of the interconnection of the steering arm 28 and reversing arm 32. Steering arm 28 is connected to a steering actuator assembly 34 which is attached to the hull or to the wall of the protective enclosure 36. The steering actuator assembly 34 is energized in response to signals from the vessels steering control mechanism which is not shown. When traveling in the forward direction as depicted in FIG. 3, energization of the steering actuator assembly 34 in response to a port turn control signal will result in actuator shaft 35 moving into restrained outer enclosure 37. This will cause the total length of the steering actuator assembly 34 to be shortened. Since the outer enclosure 37 is restrained at the hull or protective enclosure 36 and operably connected to the steering arm 28, the shortening of the actuator assembly causes the steering arm 28 to pivot about the axis of the steering shaft 22. The steering shaft 22 and steering deflector 18 being operably connected to the steering arm 28, are repositioned by the pivotal movement of the steering arm 28 to a new position as shown in FIG. 8. In response to a starboard turn control signal, the energization of the steering actuator assembly will cause the actuator shaft 35 to move out of the restrained outer enclosure 37, making the total length of the steering actuator assembly 34 longer. The operable interconnection of components that caused a pivotal displacement as described above in response to shortening the steering actuator assembly 34 will cause a pivotal displacement in the opposite direction when the steering actuator assembly 34 is lengthened. This pivotal displacement will cause the steering deflector 18 to assume a position as depicted in the ghost position of FIG. 8.

The steering deflector 18 is so shaped and positioned that it can be moved from one extreme of its arc of movement to the other while still providing an unobstructed entrance for the waterjet 10. When positioned with its longitudinal axis coincident with that of the emerging waterjet 10 as shown in FIG. 3, the waterjet 10 passes through unobstructed. When the steering deflector 18 is rotated in either direction about its axis as shown in FIG. 8 and described above, it is so constructed and positioned that the waterjet 10 will strike the side of the deflector 18, thus imparting a turning force laterally on the transom 14 of the vessel.

Referring again to FIG. 3 and FIG. 4, the reversing arm 32 is connected to a reversing actuator assembly 38 which is operatively attached to the steering arm 28. When the reversing actuator assembly 38 is not energized, its length remains fixed. During these times the steering arm 28,-the reversing arm 32 and the reversing actuator assembly 38 form the three fixed length sides of a triangle. There cannot be a pivotal displacement of the reversing arm 32 with respect to the steering arm 28 unless the length of the reversing actuator assembly 38 is changed. Since the reversing deflector l6 and reversing shaft 30 are non-pivotally attached to the reversing arm 32, as shown in FIG. 1, there cannot be a pivotal displacement between the steering deflector l8 and the reversing deflector 16 unless there is a corresponding pivotal displacement between the steering arm 28 and the reversing arm 32. Steering movements of steering arm 28, as described above and as shown in FIG. 8, will carry reversing arm 32 in combination to maintain their given positional relationship.

When the vessel is moving in a forward position, the reversing deflector 16 is maintained in a position away from the emerging waterjet 10 as shown in FIG. 3 and FIG. 5. Energization of the reversing actuator assembly 38 in response to a full reverse control signal will result in actuator shaft 39 moving into outer enclosure 41. This will cause the total length of the reversing actuator assembly 38 to be shortened. Since the reversing actuator assembly 38 forms one side of a triangle as previously described, as it shortens, the angle opposite formed by the steering arm 28 and the reversing arm 32 must get smaller as well. This pivotal displacement of the reversing arm 32 in relation to the steering arm 28 causes a direct corresponding pivotal displacement in the relationship between the steering deflector l8 and the reversing deflector 16. As the reversing arm 32 moves from its full forward position as depicted in FIG. 3 to its full reverse position as depicted in FIG. 4, the reversing deflector moves from its full forward position as shown in FIG. 3 and FIG. 5 to its full reverse position as shown in FIG. 4 and FIG. 7. In its travel from full forward to full reverse the reversing deflector will assume a plurality of positions relative to the steering deflector 18 and the emerging waterjet 10. At any of these intermediate positions as represented by FIG. 6, a portion of the waterjet 10 will be deflected, causing a reverse thrust, while the balance of the emerging waterjet 10 will continue undeflected, causing a forward thrust. At the point where the forward thrust equals the reverse thrust, the net force on the boat will be zero or a neutral position. By stopping the reverse deflector 16 in this neutral position, the vessel can remain stationary even with the waterjet pumping means at full power. It is important to note that full steering capability remains throughout the transition from forward to reverse since only the relative positions between the deflectors changes in the reversing process. The procedure as described above would reverse itself when proceeding from the full reverse positions as shown in FIG. 4 and FIG. 7 through the neutral position shown in FIG. 6 to the full forward position of FIG. 3 and FIG. 5.

Bearing and sealant means 44 are disposed as indicated to encourage ease of component movement and discourage undesired water flow.

The invention claimed is:

l. Direction control apparatus for a marine vessel employing a waterjet propulsion means wherein ambient water is drawn into an input duct and expelled as a waterjet under pressure by pump means comprising:

a. two substantially concentric shafts;

b. actuating means so interconnected with said shafts as to allow said shafts to be moved pivotally individually or in combination;

c. first deflector means carried by one of said two shafts and being in general a conduit whereby in one position the waterjet can pass unobstructed therethrough while when rotated in either direction about its axis said first deflector means will cause a deflection of the waterjet entering therein so as to provide steering control of the marine vessel; and

d. second deflector means carried by the other of said two shafts and being disposed downstream of said first deflector means and being shaped in such manner that when rotated about its axis in one position the waterjet can pass unobstructed thereby while when rotated from said position about its axis said second deflector means can assume a plurality of positions in which a portion or all of the waterjet is smoothly deflected in a generally forward direction so as to provide a reverse thrusting force on the marine vessel.

2. Direction control apparatus for a marine vessel employing a waterjet propulsion means wherein ambient water is drawn into an input duct and expelled as a waterjet under pressure by pump means comprising:

a. two substantially concentric shafts;

b. actuating means so interconnected with said shafts as to allow said shafts to be moved pivotally individually or in combination;

c. first deflector means carried by one of said two shafts and being in general a conduit whereby in one position the waterjet can pass unobstructed therethrough while when rotated in either direction about its axis said first deflector means will cause a deflection of the waterjet entering therein so as to provide steering control of the marine vessel; and

d. second deflector means carried by the other of said two shafts and being disposed downstream of said first deflector means and being curved in such manner that when rotated about its axis in one position said waterjet can pass unobstructed thereby while when rotated from said position about its axis said second deflector means can assume a plurality of positions in which a portion or all of the waterjet is smoothly deflected first to a downward and then to a generally forward direction so as to provide a reverse thrusting force on the marine vessel.

3. Direction control apparatus for a marine vessel employing a waterjet propulsion means wherein ambient water is drawn into an input duct and expelled as a waterjet under pressure by pump means comprising:

a. two substantially concentric shafts wherein the outer shaft is a conduit means containing the inner shaft;

b. actuating means so interconnected with said shafts as to allow said shafts to be moved pivotally individually or in combination;

c. first deflector means carried by the inner of said two generally concentric shafts and being in general a conduit whereby in one position the waterjet can pass unobstructed therethrough while when rotated in either direction about its axis said first deflector means will cause deflection of the waterjet entering therein so as to provide steering control of the marine vessel; and

d. second deflector means carried by the outer of said two generally concentric shafts and being disposed downstream of said first deflector means and being shaped in such manner that when rotated about its axis in one position the waterjet can pass unobstructed thereby while when rotated from said position about its axis said second deflector means can assume a plurality of positions in which a portion or all of the waterjet is smoothly deflected in a generally forward direction so as to provide a reverse thrusting force on the marine vessel.

4. Direction control apparatus for a marine vessel employing a waterjet propulsion means wherein ambient water is drawn into an input duct and expelled as a waterjet under pressure by pump means comprising:

a. two substantially concentric shafts wherein the outer shaft is a conduit means containing the inner shaft;

b. actuating means so interconnected with said shafts as to allow said shafts to be moved pivotally individually or in combination;

0. first deflector means carried by the inner of said two generally concentric shafts and being in general a conduit whereby in one position the waterjet can pass unobstructed therethrough while when rotated in either direction about its axis said first deflector means will cause a deflection of the waterjet entering therein so as to provide steering control of the marine vessel; and

d. second deflector means carried by the outer of said two generally concentric shafts and being disposed downstream of said first deflector means and being curved in such manner that when rotated about its axis in one position the waterjet can pass unobstructed thereby while when rotated from said position about its axis said second deflector means can assume a plurality of positions in which a portion or all of the waterjet is smoothly deflected first to a downward and then to a generally forward direction so as to provide a reverse thrusting force on the marine vessel.

5. Direction control apparatus for a marine vessel employing a waterjet propulsion means wherein ambient water is drawn into an input duct and expelled as a waterjet under pressure by pump means comprising:

a. two substantially concentric shafts;

first of said two shafts;

c. second actuating means operatively connected to the second of said two shafts; said first actuating is smoothly deflected in a generally forward direction so as to provide a reverse thrusting force on the marine vessel.

means being so interconnected with said. second actuating means that energization of said second actuating means will cause a pivotal displacement in the disposition of said outer shaft in relation to means being so lntefcolmficted with Said Second the disposition of said inner shaft while energizaactuating means that energlzatlon of Sald Second tion of said first actuating means will cause a joint actuallng means will Cause a Plvotal dlsplacement pivotal motion of both said two shafts in combinain the disposition of said second shaft in relation to i and no pivotal displacement therebetween; the disposition of said first shaft while energization fi t d fl t means carried by the inner f Said of Sald flrst actuating {mans will callse a j l R 10 two shafts and being in general a conduit whereby 0m] of Q Sald two shafts Combmatlon in one position the waterjet can pass unobstructed and pwotal dlsplacemfint herePetween; therethrough while when rotated in either direction deflector means earned by Sald first Shaft and about its axis said first deflector means will cause bemg in general a Conduit whereby in one position a deflection of the waterjet entering therein so as the waterjet can pass unobstructed therethrough to provide steering control of the marine vessel; whilewhen rotated in either direction about its axis and sad first d means W Cause a deflecnon of e. second deflector means carried by the outer of said waterjet emenng fllerem so as to provide Steer two shafts and being disposed downstream of said mg control of the marme fi and first deflector means and being shaped in such second deflector means carried by said second man th t h t t d b t shaft and being disposed downstrean of said first er a w m a e a ou l S axis m one podeflector means and being shaped in such manner the waterjet can pas.s unopftructed h y that when rotated from said position about its axis l' when rotated from sald posmon about us l said second deflector means can assume a plurality Sald j f F mean? can assume a plurallty of positions in which a portion or all of the waterjet of posmons m whlch a porno or all of the waterjet is smoothly deflected first to a downward and then to a generally forward direction so as to provide a reverse thrusting force on the marine vessel.

7. Direction control apparatus for a marine vessel as claimed in claim 1 wherein said two substantially concentric shafts pass through the hull of the marine vessel, said actuating means being disposed within the hull of the marine vessel.

8. Direction control apparatus for a marine vessel as a. two substantially concentric shafts wherein the outer shaft is a conduit means containing the inner shaft;

b. first actuating means operatively connected to the inner of said two shafts;

c. second actuating means operatively connected to the outer of said two shafts;'-'said first actuating claimed in claim 1 wherein said two substantially concentric shafts pass through the surface of a protective enclosure associated with the marine vessel, said actuating means being disposed within said protective enclosure. 

1. Direction control apparatus for a marine vessel employing a waterjet propulsion means wherein ambient water is drawn into an input duct and expelled as a waterjet under pressure by pump means comprising: a. two substantially concentric shafts; b. actuating means so interconnected with said shafts as to allow said shafts to be moved pivotally individually or in combination; c. first deflector means carried by one of said two shafts and being in general a conduit whereby in one position the waterjet can pass unobstructed therethrough while when rotated in either direction about its axis said first deflector means will cause a deflection of the waterjet entering therein so as to provide steering control of the marine vessel; and d. second deflector means carried by the other of said two shafts and being disposed downstream of said first deflector means and being shaped in such manner that when rotated about its axis in one position the waterjet can pass unobstructed thereby while when rotated from said position about its axis said second deflector means can assume a plurality of positions in which a portion or all of the waterjet is smoothly deflected in a generally forward direction so as to provide a reverse thrusting force on the marine vessel.
 2. Direction control apparatus for a marine vessel employing a waterjet propulsion means wherein ambient water is drawn into an input duct and expelled as a waterjet under pressure by pump means comprising: a. two substantially concentric shafts; b. actuating means so interconnected with said shafts as to allow said shafts to be moved pivotally individually or in combination; c. first deflector means carried by one of said two shafts and being in general a conduit whereby in one position the waterjet can pass unobstructed therethrough while when rotated in either direction about its axis said first deflector means will cause a deflection of the waterjet entering therein so as to provide steering control of the marine vessel; and d. second deflector means carried by the other of said two shafts and being disposed downstream of said first deflector means and being curved in such manner that when rotated about its axis in one position said waterjet can pass unobstructed thereby while when rotated from said position about its axis said second deflector means can assume a plurality of positions in which a portion or all of the waterjet is smoothly deflected first to a downward and then to a generally forward direction so as to provide a reverse thrusting force on the marine vessel.
 3. Direction control apparatus for a marine vessel employing a waterjet propulsion means wherein ambient water is drawn into an input duct and expelled as a waterjet under pressure by pump means comprising: a. two substantially concentric shafts wherein the outer shaft is a conduit means containing the inner shaft; b. actuating means so interconnected with said shafts as to allow said shafts to be moved pivotally individually or in combination; c. first deflector means carried by the inner of said two generally concentric shafts and being in general a conduit whereby in one position the waterjet can pass unobstructed therethrough while when rotated in either direction about its axis said first deflector means will cause deflection of the waterjet entering therein so as to provide steering control of the marine vessel; and d. second deflector means carried by the outer of said two generally concentric shafts and being disposed downstream of said first deflector means and being shaped in such manner that when rotated about its axis in one position the waterjet can pass unobstructed thereby while when rotated from said position about its axis said second deflector means can assume a plurality of positions in which a portion or all of the waterjet is smoothly deflected in a generally forward direction so as to provide a reverse thrusting force on the marine vessel.
 4. Direction control apparatus for a marine vessel employing a waterjet propulsion means wherein ambient water is drawn into an input duct and expelled as a waterjet under pressure by pump means comprising: a. two substantially concentric shafts wherein the outer shaft is a conduit means containing the inner shaft; b. actuating means so interconnected with said shafts as to allow said shafts to be moved pivotally individually or in combination; c. first deflector means carried by the inner of said two generally conceNtric shafts and being in general a conduit whereby in one position the waterjet can pass unobstructed therethrough while when rotated in either direction about its axis said first deflector means will cause a deflection of the waterjet entering therein so as to provide steering control of the marine vessel; and d. second deflector means carried by the outer of said two generally concentric shafts and being disposed downstream of said first deflector means and being curved in such manner that when rotated about its axis in one position the waterjet can pass unobstructed thereby while when rotated from said position about its axis said second deflector means can assume a plurality of positions in which a portion or all of the waterjet is smoothly deflected first to a downward and then to a generally forward direction so as to provide a reverse thrusting force on the marine vessel.
 5. Direction control apparatus for a marine vessel employing a waterjet propulsion means wherein ambient water is drawn into an input duct and expelled as a waterjet under pressure by pump means comprising: a. two substantially concentric shafts; b. first actuating means operatively connected to the first of said two shafts; c. second actuating means operatively connected to the second of said two shafts; said first actuating means being so interconnected with said second actuating means that energization of said second actuating means will cause a pivotal displacement in the disposition of said second shaft in relation to the disposition of said first shaft while energization of said first actuating means will cause a joint pivotal motion of both said two shafts in combination and no pivotal displacement therebetween; d. first deflector means carried by said first shaft and being in general a conduit whereby in one position the waterjet can pass unobstructed therethrough while when rotated in either direction about its axis said first deflector means will cause a deflection of the waterjet entering therein so as to provide steering control of the marine vessel; and e. second deflector means carried by said second shaft and being disposed downstrean of said first deflector means and being shaped in such manner that when rotated from said position about its axis said second deflector means can assume a plurality of positions in which a portion or all of the waterjet is smoothly deflected in a generally forward direction so as to provide a reverse thrusting force on the marine vessel.
 6. Direction control apparatus for a marine vessel employing a waterjet propulsion means wherein ambient water is drawn into an input duct and expelled as a waterjet under pressure by pump means comprising: a. two substantially concentric shafts wherein the outer shaft is a conduit means containing the inner shaft; b. first actuating means operatively connected to the inner of said two shafts; c. second actuating means operatively connected to the outer of said two shafts; said first actuating means being so interconnected with said second actuating means that energization of said second actuating means will cause a pivotal displacement in the disposition of said outer shaft in relation to the disposition of said inner shaft while energization of said first actuating means will cause a joint pivotal motion of both said two shafts in combination and no pivotal displacement therebetween; d. first deflector means carried by the inner of said two shafts and being in general a conduit whereby in one position the waterjet can pass unobstructed therethrough while when rotated in either direction about its axis said first deflector means will cause a deflection of the waterjet entering therein so as to provide steering control of the marine vessel; and e. second deflector means carried by the outer of said two shafts and being disposed downstream of said first deflector means and being shaped in such manner that when rotated about its axis in one position the waterjet Can pass unobstructed thereby while when rotated from said position about its axis said second deflector means can assume a plurality of positions in which a portion or all of the waterjet is smoothly deflected first to a downward and then to a generally forward direction so as to provide a reverse thrusting force on the marine vessel.
 7. Direction control apparatus for a marine vessel as claimed in claim 1 wherein said two substantially concentric shafts pass through the hull of the marine vessel, said actuating means being disposed within the hull of the marine vessel.
 8. Direction control apparatus for a marine vessel as claimed in claim 1 wherein said two substantially concentric shafts pass through the surface of a protective enclosure associated with the marine vessel, said actuating means being disposed within said protective enclosure. 